Method of making a precast decorative panel

ABSTRACT

A precast decorative panel is formed by filling a flexible mold to a selected level with an unset thermosetting resin and aggregates. After a nonrigid member, which is smaller than the receptacle, is placed on top of the mixture of resin and aggregates, a filler mold, which is smaller than the receptacle and substantially the same configuration so as to form a substantially uniform space therebetween, is disposed within the receptacle. This uniform space is filled with aggregates and an unset thermosetting resin. After the unset resin is partially cured to a soft gel, the filler mold is removed. Then, the partially cured resin is separated from the mold. This produces a panel having a textured top surface and a bottom surface with a drop edge extending therefrom along the entire periphery of the body of the panel.

United States Patent [72] inventor Frank R. Smith 3461 Lansdowne Drive,Lexington, Ky.

. 40502 [2i] Appl. No. 12,671 [22] Filed Feb. I9, 1970 |23| Division ofSer. No. 842,806, July 7, i969, which is a continuation of Ser. No.7li,l47,

Feb. I6, I968, abandoned, which is a continuation-in-part of Ser. No.455,831, May 14,1965, abandoned. [45] Patented Sept. 21, 1971 [54]METHOD OF MAKING A PRECAST DECORATIVE PANEL 22 Claims, 9 Drawing Figs.

[52] U.S.Cl 264/162, 264/256, 264/257, 264/273, 264/275 [51] lnt.C| 829d3/02 [50] Field of Search 264/162, 247, 255, 273, 275, 246, 256

[56] References Cited UNITED STATES PATENTS 1,169,985 2/l9l6 Mickelson264/255 3,09l,i76 5/1963 Wall..... H 264/27I X e:seemeaaaaam emss.

Primary Examiner- Robert F. White Assistant Examiner-Allen M. SokalA!t0rneyFrank C. Leach, Jr.

ABSTRACT: A precast decorative panel is formed by filling a flexiblemold to a selected level with an unset thermosetting resin andaggregates. After a nonrigid member, which is smaller than thereceptacle, is placed on top of the mixture of resin and aggregates, afiller mold, which is smaller than the receptacle and substantially thesame configuration so as to form a substantially uniform spacetherebetween, is disposed within the receptacle. This uniform space isfilled with aggregates and an unset thermosetting resin. After the unsetresin is partially cured to a soft gel, the filler mold is removed.Then, the partially cured resin is separated from the mold. Thisproduces a panel having a textured top surface and a bot tom surfacewith a drop edge extending therefrom along the entire periphery ofthebody ofthe panel.

SHEET 1 [IF 3 INVENTOR FRANK R. SMITH ATTORNEY PATENIEDSEP21 I971PATENTEUsEPm I971 3-608,038

sum 3 or 3 I METHOD OF MAKING A PRECAST DECORATIVE PANEL This is adivision of application Ser. No. 842,806, filed July 7, 1969, which is acontinuation of application Ser. No. 71 L147, filed Feb. l6,,l968, andnow abandoned, which is a continuation-in-part of application Ser. No.455,831, filed May 14, 1965, and now abandoned.

This invention relates to a method of making a precast decorative paneland, more particularly, to a method of making a precast decorative panelwherein the panel is employed as a kitchen countertop, a vanity top, atabletop or the like.

The precast decorative panel of the present invention is formed of atransparent or substantially transparent polyester resin havingaggregates therein such as shells, marble chips, or the like. Thus, theaggregates, which are a filler, may be viewed through the resin. 7

in order that the panel may be employed as a kitchen countertop, vanitytop, tabletop or the like, one of its surfaces must be flat or texturedand level. A flat or textured and level surface results from resinaround some of the aggregates receding therefrom during curing wherebywear will occur on the aggregates rather than the resin so as not tocause fogging of the clear or substantially clear resin due to minutescratches. If the panel has a smooth, level surface rather than a flator textured and level surface, wear would occur on the resin toeventually cause it to become opaque due to small scratches thereon sothat the aggregates could not be viewed through the resin.

One suggested method of forming a precast decorative panel of apolyester resin with aggregates therein is described in US. Pat. No.3,097,080 to weir. However, when a precast decorative panel is formedusing the method described in the I aforesaid Weir patent, severalproblems arise.

When the method of the aforesaid Weir patent is employed, the completesurface, which is exposed when the plague is formed in the mold, must beground to remove the protruding aggregates extending beyond the surfaceof the cured polyester resin. This large amount of grinding is both timeconsuming and expensive.

When the polyester resin is disposed within the mold as described in theaforesaid Weir patent with aggregates added thereto, uncontrollabledistortion occurs during curing thereof after the mixture is removedfrom the mold. If the unexposed surface should distort rather than theexposed surface, the artificial stone plaque of Weir could not beutilized as a kitchen countertop, vanity top, tabletop, or the likebecause it would be necessary to grind the unexposed surface as well asthe exposed surface. Grinding of both of the surfaces would result inboth surfaces being smooth and level rather than the unexposed surfacehaving a flat or textured and level surface.

Furthermore, when using the method of the aforesaid Weir patent, thequantity of material employed is substantial because of the thickness ofthe product. However, the thickness is necessary when the product isused as a kitchen countertop or the like to provide the desired sideedge appearance.

The present invention overcomes the disadvantage of this added expenseof material by forming a body of sufficient thickness for support buthaving only a depending flange extending from the periphery to form thedrop edge with the center being hollow. This arrangement not onlydecreases the weight of the material but also reduces the grinding sinceonly the surface of the flange must be ground. Thus, a substantialsaving in time and expense is provided by the present invention.

in forming the product of the present invention, the

polyester resin is supplied to a receptacle in the mold to the desiredlevel. The receptacle has the shape or configuration in which theproduct is to be formed. The aggregates are added to the polyester resinto produce the desired thickness of the body of the product of thepresent invention. In order to form the flange, which extends only fromthe periphery of the body to form the drop edge, it is necessary to usea filler mold. The filler mold has the same configuration as thereceptacle but of slightly smaller size to form a substantially uniformspace between the filler mold and the receptacle so that the drop edgewill be of substantially uniform thickness. The uniform space betweenthe filler mold and the receptacle is then filled with polyester resinand aggregates to the level of the top of the receptacle.

Since the polyester resin cures at room temperature when a catalyst isadded thereto, the product partially cures within approximately 30minutes to a soft gel or rubberylike substance. If the filler mold isremoved and the partially cured mixture, which forms the decorativepanel, is then separated from the mold, distortion occurs in a convexdirection of the surface, which would form the top surface of a kitchencountertop or the like, during the remainder of the curing cycle, whichtakes approximately 12 hours. Thus, it would be necessary to grind thisentire top surface to produce a level surface. However, the top surfacewould be smooth rather than textured or flat so that wear would occur onthe resin rather than the aggregates whereby the resin eventuallybecomes opaque. Thus, the product could not be satisfactorily used as akitchen countertop or the like. If a satisfactory product could beproduced by grinding, it also would be necessary to grind the surface ofthe flange, which forms the drop edge, to remove the protrudingaggregates.

If the filler mold is a rigid material and is allowed to remain as apermanent stabilizer, distortion of the surface, which would form thetop surface of a kitchen counter or the like, occurs in a concavedirection when the mixture completes its curing in approximately 12hours. Again, it would be necessary to grind the entire top surface toproduce a level surface. Of course, the surface would be smooth ratherthan flat or textured, and this is not satisfactory as previouslymentioned.

The use of the filler mold, either only during partial curing or as apermanent stabilizer, creates a hollow center to reduce the quantity ofmaterial used. Therefore, the expense of the material is decreased.Additionally, the amount of grinding along the bottom surface where theaggregates protrude from the polyester resin is reduced since only theflange, which forms the drop edge, must be ground. However, grinding ofthe top surface eliminates the textured or flat surface, which isrequired to provide a satisfactory product. Even if grinding of the topsurface due to distortion created a satisfactory product, this extragrinding increases the cost.

The present invention eliminates distortion when a filler mold isemployed by utilizing a nonrigid member, which is porous so as to not bea barrier to the flow of the resin, as a permanent stabilizer. Thenonrigid and porous member may be a mat of glass fibers or an open meshmember, for example.

When the nonrigid member is employed, the filler mold is removed afterpartial curing and no distortion occurs during complete curing of thepolyester resin. Thus, only grinding of the surface of the drop edgefrom which the aggregates protrude is required. Accordingly, a quantityof material is saved by having a hollow center area, and the amount ofgrinding is substantially reduced while still producing a flat ortextured and level top surface, which is a prerequisite for a kitchencountertop, vanity top, tabletop, or the like. Since the top surface isnot ground in forming the product by the method of the presentinvention, the resin around some of the aggregates has receded slightlyto form the desired textured or flat surface wherein wear occurs on theaggregates rather than the resin. Accordingly, the resin does not becomeopaque as it would if the surface is ground.

An object of this invention is to provide a method for economicallyforming a precast decorative panel.

Other objects of this invention will be readily perceived from thefollowing description, claims, and drawings.

This invention relates to a method of forming a precast decorative panelincluding including filling a receptacle in a mold with an unsetthermosetting resin and aggregates to a selected level and placing anonrigid member within the receptacle on top of the mixture of resin andaggregates. A form, which is of smaller size than the nonrigid memberand of the same configuration as the receptacle but smaller size to forma substantially uniform space therebetween, is then placed on top of thenonrigid member. The uniform space between the form and the walls of thereceptacle is filled with aggregates and an unset thermosetting resin.The unset resin is cured, and the form is removed after the resin hascured to at least a soft gel. The cured resin including the aggregatesand the nonrigid member is separated from the mold.

This invention also relates to a method of forming a precast decorativepanel having an opening therein. The method includes disposing a moldmember within a receptacle in a mold with the mold member beingsubstantially smaller than the receptacle. The portion of the receptaclenot having the mold member is then filled with an unset thermosettingresin and aggregates to a selected level. At least one nonrigid memberis next placed on top of the mixture of resin and aggregates ex cept forthe portion of the mixture between the mold and the adjacent walls ofthe receptacle. Support bars are placed in the portion of the mixturebetween the mold member and the adjacent walls of the receptacle. Next,a form, which is the same configuration as the receptacle but smallersize to form a substantially uniform space therebetween, is placed ontop of the nonrigid member and the mold member. The uniform spacebetween the form and the walls of the receptacle is filled withaggregates and an unset thermosetting resin. The unset resin is cured.The form and the mold member are removed from the resin after it hascured to at least a soft gel. The resin including the aggregates and thenonrigid member is separated from the mold.

The attached drawings illustrate preferred embodiments of the invention,in which:

FIG. 1 is a perspective view, partly in section, illustrating a portionof the apparatus for carrying out the method of the present invention;

FIG. 2 is a perspective view from another direction of a portion of theapparatus of FIG. 1 and showing the remainder of the apparatus forcarrying out the method of the present invention;

FIG. 3 is a sectional view of a mold and its support structure formingthe decorative panel of the present invention in one shape;

FIG. 4 is a perspective view partly in section and taken from the bottomside, of the precast decorative panel formed by the mold of FIG. 3;

FIG. 5 is a sectional view of a mold forming a precast decorative panelof another shape;

FIG. 6 is a perspective view, partly in section and taken from the topside, of a portion of the precast decorative panel formed by the moldofFIG. 5;

FIG. 7 is a perspective view, partly in section and taken from thebottom side, of another form of a precast decorative panel formed by themold of FIG. 3;

FIG. 8 is an enlarged sectional view of a portion of the panel of FIG.7; and

FIG. 9 is a perspective view, partly in section and taken from the topside, of a portion of another embodiment of a precast decorative panelformed by the mold of FIG. 5.

Referring to the drawings and particularly FIGS. 1 and 2, there is shownan apparatus for forming the product of the present invention. Theapparatus includes a work or support table 10 disposed adjacent one sideof a curing bin 11.

The curing bin 11 includes a top wall 12, a bottom wall 14, and endwalls 15 and 16. The curing bin 11 has a pivotally mounted door 17,which closes an opening 18 in the side of the curing bin 11 adjacent thetable 10.

The bottom wall 14 of the curing bin 11 is horizontally disposed toprovide a level surface. Likewise, the work table 10 is positioned sothat its top provides a level surface.

The bottom wall 14 of the curing bin 11 has a plurality of parallel,roller support members 19 fixed thereto and extending from one side ofthe curing bin 11 to the other side. The bottom wall 14 of the curingbin 11 has three parallel, movable roller support members 20 disposedadjacent the opening 18 for movement therethrough. Each of the movableroller support members 20 slides on a guide 21, which is fixed to thebottom wall 14 of the curing bin 11.

The work table 10 has three support blocks 22 extending from its side,which is adjacent the curing bin 11, to receive the ends of the movableroller support members 20 when they are extended through the opening 18.The support blocks 22 are positioned to maintain the roller supportmembers 20 horizontal and level when they are moved from completelywithin the curing bin 11 to the positions in which their extended endsare supported by the blocks 22 as shown in FIG. 1.

As shown in FIG. 1, a carrier board 23, which is preferably formed ofplywood, is positioned on the top of the work table 10. The carrierboard 23 supports a mold 24, which is flexible and preferably formed ofa high-pressure plastic laminated material.

The mold has a bottom wall and sidewalls with open ends. The open endsof the mold are closed by members 25, which are preferably formed ofplywood, If desired, the end walls could be formed integral with theremainder of the mold 24 and of the same material. However, the use ofthe movable members 25 permits utilization of the mold 24 to formproducts of various sizes.

When the members 25 are disposed between the sidewalls of the mold 24, areceptacle 26 is formed therein. As shown in FIG. 1, the receptacle 26is rectangular shaped. The walls of the receptacle 26 are coated with asuitable material such as PVA parting film, which is sold by theSherwin-Williams Co. as Code W 65.

A mixing tank 27 is supported on top of a support table 28. The mixingtank 27 has a first conduit 29 leading to a supply tank (not shown)containing a clear or transparent or substantially clear or transparentpolyester resin, which will cure at room temperature.

One example of a suitable polyester resin is the low viscosity, roomtemperature curing resin, which is sold under the trademark SELECTRON 51I9 by Pittsburgh Plate Glass Company. The resin is the reaction productof an alpha-beta unsaturated carboxylic acid, phthalic anhydride, and aglycol. It is blended with styrene, and the composition also contains asmall amount of parafiin. It should be understood that any othersuitable thermosetting plastic resin, which has the properties of curingat room temperature and being clear or transparent or substantiallyclear or transparent may be utilized.

A second conduit 30 extends from the table 27 to a catalyst tank (notshown). When the polyester resin is SELECTRON 5 I 19, the catalyst ispreferably methyl ethyl ketone peroxide. In order to produce the desiredcuring, approximately 1 percent of the mixture is the methyl ethylketone peroxide while the remainder is SELECTRON 51 19 polyester resin.

The mixing tank 27 has a flexible conduit 31 to permit the polyesterresin and catalyst to be supplied from the mixing tank 27 to thereceptacle 26. A knob 32 regulates a value (not shown) to control theflow from the mixing tank 27 through the conduit 31.

After the polyester resin has been added to the receptacle 26,aggregates, which may be shells, marble chips, or other similarmaterial, are added as a filler to the polyester resin within thereceptacle 26 of the mold 24. The preferred minimum size of theaggregates is No. 1 or 2, which is approximately one-fourth inch whilethe preferred maximum size is No. 6, which is approximatelythree-fourths inch. If it is desired for the end product to have a colorother than the natural color of the aggregates, the aggregates arecolored. The preferred level of the polyester resin and the aggregatesis approximately one-half inch when using the aggregates of N o. l or 2size.

When it is desired for the end product to have a color other than thenatural color of the aggregates, it should be understood that the resinmay be tinted rather than the aggregates being colored. Thus, the resinis still transparent or substantially transparent even though it istinted so that the aggregates within the resin may still be viewed.

A nonrigid member, which is porous so as to not be a barrier to the flowof the resin, is placed on top of the resin and aggregates. One suitableexample of the nonrigid member is an open mesh member 33 such as a wirescreen (see FIG. 3), for example. As shown in FIG. 3, the width of theopen mesh member 33 is slightly less than the width of the receptacle26. The length of the open mesh member 33 is slightly less than thelength of the receptacle 26.

The size of the open mesh member 33 depends upon the I amount ofshrinkage of the resin, which is employed, and the size of theaggregates. When using SELECTRON 5119 polyester resin and aggregates ofNo. l or 2 size, a wire screen having a gauge of 27 and a mesh of 8 issatisfactory.

The use of the open mesh member 33 allows the resin to cure without anydistortion of the product. This is because the open mesh member 33permits less shrinkage of the resin adjacent thereto then occurs at thebottom of the receptacle 26. This is necessary because there is lessresin at the bottom of the receptacle 26 due to the aggregatescollecting at the bottom because of gravity. Thus, there is more resinto be cured at the top, and the open mesh member 33 compensates for thisdifference in quantity of resin to be cured to eliminate distortion.

It should be understood that the use of a wire screen of different gaugeand/or mesh may be necessary when the width of the receptacle 26 exceeds24 inches. Of course, if desired, the same gauge and mesh wire screenmay be employed but it may be necessary to cut the open mesh member 33along its entire length to relieve tension therein during curing; thiswould depend on the resin. When the open mesh member 33 is cut, theparts slightly overlap.

A filler mold or form 34, which is preferably formed of particle board,is positioned on top of the open mesh member 33. The mold 34, which issmaller than the open mesh member 33, is smaller than the receptacle 26so that a substantially uniform space is formed between the mold 34 andthe walls of the receptacle 26. This uniform space is filled withpolyester resin from the mixing tank 27 and aggregates until the mixtureis level with the top of the mold 24 as shown in FIG. 3.

After the receptacle 26 of the mold 24 has been completely filled, themovable roller support members 20 are disposed on the support blocks 22so that the mold 24 may be slid from the work table 10 onto the fixedroller support members 19 within the curing bin 11. Since the topsurfaces of the roller support members 20 form a continuation of the topsurface of the table 10, the mold 24 is maintained level in itstransportation from the work table 10 to the curing bin 1 l to preventany loss of resin from the receptacle 26.

Prior to being moved into the curing bin 11 from the work table 10 orjust after entering the curing bin 11, a plurality of weights (notshown) is disposed in spaced relation to each other on top of the fillermold 34. These weights maintain the filler mold 34 in position whenpartial curing occurs within the curing bin 11.

The mold 24 is advanced through the curing bin 1 1 by other of the molds24 being disposed on the work table 10 and filled as previously.described. These molds are then advanced into the curing bin 11 to movethe first of the molds 24 therethrough.

A duct 35, which communicates with the interior of the curing bin 11through the end wall 15, has an air conditioning unit 35' disposedtherein. The duct 35 connects the interior of the curing bin with theatmosphere. A thermostat (not shown) maintains the temperature of theinterior of the curing bin 11 at a selected value, which is preferably72 F.

A portion of the air which is exhausted from the curing bin 11 isreturned thereto through the evaporator of the air conditioning unit35'. The remainder of the air, which is exhausted from the curing bin 11by the air conditioning unit 35, is directed over the condenser of theair conditioning unit 35 and then exhausted from the unit 35' to theatmosphere through the duct.

As shown in FIG. 2, the curing bin 11 has a second side opening 36,which is closed by a pivotally mounted door 37.

Three parallel, movable roller support members 38 are slidably mountedon guides 39, which are fixed to the bottom wall 14 of the curing bin 1I.

When the movable roller support members 38 extend through the opening 36with the door 37 in the position of FIG. 2, they rest on support blocks(not shown) on the side of a work or support table 40. The top of thework or support table 40 is level.

When one of the carrier boards 23 is disposed on the roller supportmembers 38 with the mold 24 resting thereon, the movement of the rollersupport members 38 to the position of FIG. 2 permits the removal of thecarrier board 23 and the mold 24 from the interior of the curing bin 11.Because the roller support members 38 are disposed slightly below thetop of the table 40, the carrier board 23 is prevented from moving ontothe top surface of the work table 40 but abuts against the side thereof.Thus, the mold 24 is easily removed from the carrier board 23 aftercuring has been completed within the interior of the curing bin 11. Itshould be understood that the weights (not shown) are removed from thefiller mold 34 before removal of the carrier board 23 from the curingbin 11.

The carrier board 23 is then disposed on two parallel, roller supportmembers 41, which are disposed on opposite ends of the top wall 12 ofthe curing bin 11. The support members 41 slant from the side having theopening 36 to the side having the opening 18 to allow the carrier board23 to return toward the work table 10 by gravity.

The mold 24 is retained within the curing bin 11 for approximately 30minutes. At the end of this time, the polyester resin has been formedinto a soft gel.

Of course, the time of gelation is determined by the composition of theresin and the temperature, which is maintained within the interior ofthe curing bin 11. Thus, shorter gel times occur with highertemperatures, and longer gel times occur with lower temperatures.Furthermore, the percent of the catalyst also varies the amount of time.Accordingly, an increase in the percentage of the methyl ethyl ketoneperoxide would reduce the time of gelation while a decrease wouldincrease the time of gelation.

When the polyester resin with the aggregates therein becomes a soft gel,the mixture is a rubberylike substance. Since the mold 24 is preferablyflexible, the mixture is easily separated therefrom in its formedconfiguration. It should be understood that the filler mold 34 ispreferably removed from the mixture before the mixture is separated fromthe mold 24 but could be removed after the mold 24 is separated from themixture or simultaneously therewith.

The empty mold 24 is then placed on top of the carrier board 23, whichis resting on the roller support members 41. However, the end members 25are withdrawn before the mold 24 is positioned on top of the carrierboard 23.

The rubberylike mixture, which is rectangular in shape because this isthe shape of the receptacle 26 within the mold 24, is positioned on acarrier board 42. The carrier board 42 rides on rollers 43, which aresupported on a table 44.

One end of the carrier board 42 has a flexible member 45 connectedthereto. The other end of the flexible member 45 is connected to weights(not shown) or other suitable means to exert a constant force on thecarrier board 42 to move it along the rollers 43.

As shown in FIGS. 2 and 4, the rubberylike mixture forms a decorativepanel 46 having a flange 47 extending from one side thereof around theentire periphery of the panel 46. The flange 47 will have aggregatesextending through the polyester resin in the surface, which was exposedwhen in the mold 24. Likewise, the polyester resin may not be completelylevel. Therefore, it is necessary to grind the exposed surface of theflange 47.

Accordingly, the decorative panel 46 is positioned on the carrier board42 and pulled beneath a grinding roller 48. which is driven by anelectric motor 49 through a pulley 50. An exhaust duct 51 is placedabove the grinding roller 48 to remove the particles, which are groundfrom the panel 46 by the grinding roller 48. An exhaust fan (not shown)is disposed within the duct 51 to vent the removed particles to theatmosphere.

The weights (not shown), which are attached to the flexible member 45,pull the decorative panel 46 through the roller 48 in accordance withthe grinding. Thus, the carrier board 42 moves slower when either end ofthe decorative panel 46 is passing beneath the roller 48 because of thegreater amount of required grinding due to the larger surface area.

The decorative panel 46 is removed from the carrier board 42 and allowedto harden for approximately 12 hours. At this time, it has 90 percent ofits hardness and is rigid. However, the resin continues to setthroughout the life of the product in the same manner as concrete does.

As previously mentioned, in forming the decorative panel 46, the resinwas disposed in the mold before the aggregates were added thereto. As aresult, when the aggregates pass through the resin to reach the bottomof the mold, they become coated with the resin because of the viscosityof the resin.

Thus, when the resin recedes or shrinks from around the aggregates atthe surface of the decorative panel 46 during curing, the decorativepanel 46 has its textured or flat surface formed by the resin beingdisposed beneath the upper surfaces of the aggregates between theaggregates due to the resin receding or shrinking from around theseaggregates during curing.

When the decorative panel 46 (see FIG. 4) is utilized as a kitchencountertop, a vanity top, a tabletop, or the like, the panel 46 isinverted from the position of FIG. 4 to permit the unexposed surface,which is textured or flat, to be the top surface. That is, the screen 33is on the bottom surface and the depending flange 47 extends from thebottom surface of the body of the panel 46 to form the drop edge. Thescreen 33 is completely hidden from view by the flange 47.

When it is desired to form a decorative panel to surround and support akitchen sink, a range top, washbasin, or the like when the panel isemployed as a kitchen countertop, a vanity top, or the like, forexample, an opening must be provided within the decorative panel toreceive the sink, washbasin, range top, or other structure. A portion ofa decorative panel 52 having an opening 53 therein for the sink,washbasin, range top, or the like is shown in FIG. 6.

The decorative panel 52 is formed with one of the molds 24 insubstantially the same manner as described with respect to thedecorative panel 46. However, a mold member 54 (see FIG. which is of theshape and size of the opening 53 in the decorative panel 52, isinitially disposed within the receptacle 26 of the mold 24 after themold 24 is coated with PVA parting film or the like. The mold member 54,which is preferably plywood, must be placed at the desired positionwithin the receptacle 26 to correspond with the position of the opening53 in the decorative panel 52.

Clear or transparent or substantially clear or transparent polyesterresin and its catalyst are supplied from the mixing tank 27 to thereceptacle 26 of the mold 24 after the mold member 54 is positionedwithin the receptacle 26. The resin and its catalyst are not supplied tothe portion of the receptacle 26 having the mold member 54 therein.After the resin is supplied, the aggregates are added to the resin toform a mixture of a selected level. When the aggregates are No. l or 2in size, the preferred level of the mixture of the resin and theaggregates is one-half inch.

At least one of the open mesh members 33 is disposed within thereceptacle 26 on top of the mixture of the resin and aggregates.However. no open mesh member 33 fits over the mold member 54 since thisarea must remain open to form the opening 53 in the decorative panel 52.

If the opening 53 were at one end of the decorative panel 52, only oneof the open mesh members 33 would be employed. Otherwise, two of theopen mesh members are required with one disposed on each end of the moldmember 54.

In the same manner as employed in forming the decorative panel 46, eachof the open mesh members 33 terminates short of the sidewalls of thereceptacle 26 of the mold 24 as shown in FIG. 5. The open mesh members33 also terminate short of the end walls of the receptacle 26. If thewidth of the receptacle 26 is greater than 24 inches, each of the openmesh members may be cut longitudinally along its entire length torelieve tension in the same manner as described in forming thedecorative panel 46.

Since the open mesh members 33 cannot be disposed on top of the moldmember 54, which forms the opening 53 in the decorative panel 52,strength and stability must be provided in the area of the decorativepanel 52 adjacent the opening 53. Accordingly, rods 55 are disposedwithin the mixture of the polyester resin and the aggregates after theopen mesh members 33 have been positioned. These rods are preferablythreeeighths inch in diameter and formed of steel. As shown in FIG. 6,each of the rods 55 extends a greater length than the opening 53 toprovide the desired stability and strength to insure that the decorativepanel 52 does not distort during curing.

It should be understood that no open mesh member is disposed on top ofthe resin and aggregate mixture, which is within the receptacle 26between the mold member 54 and the adjacent walls of the receptacle 26.If the mold member 54 is disposed at one end of the receptacle 26 sothat only one of the open mesh members 33 is employed, the open meshmember 33 is not disposed on top of the mixture of resin and aggregateswithin the receptacle 26 between the mold member 54 and the adjacent endwall of the receptacle 26 and between the mold member 54 and theadjacent sidewalls of the receptacle 26. If the mold member 54 isdisposed within the receptacle 26 so that one of the open mesh members33 is disposed on each end of the mold member 54, the open meshmembers'33 are not disposed on top of the mixture of the resin and theaggregates within the receptacle 26 between the mold member 54 and theadjacent sidewalls of the receptacle 26.

The filler mold 34 is then positioned within the receptacle 26 on top ofthe mold member 54 as shown in FIG. 5. The filler mold 34 extends overboth the mold member 54 and the open mesh member 33.

As shown in FIG. 5, the tiller mold 34 is smaller than the receptacle 26and the open mesh member 33 but slightly larger than the mold member 54.The filler mold 34 cooperates with the walls of the receptacle 26 toprovide a substantially uniform space therebetween.

The mixing of the resin and catalyst is supplied from the mixing tank 27to fill the uniform space between the filler mold 34 and the walls ofthe receptacle 26. Aggregates also are added, preferably before themixture of the resin and the catalyst from the mixing tank. The mixtureof the aggregates and the resin is level with the top of the mold 24.

Thereafter, the mold 24 is moved from the work or support table 10 intothe interior of the curing bin 11 as previously described when formingthe decorative panel 46. Of course, weights are disposed on top of thefiller mold 34 before curing begins in the curing bin 11.

When the mold 24 has been disposed within the curing bin 11 forapproximately 30 minutes, it is removed in the same manner as describedfor the decorative panel 46. Thus, the movable roller support members 38are extended to the position of FIG. 2, and the carrier board 23 isprevented from moving onto the top surface of the table 40. Of course,the weights are removed before the mold 24 is removed from the curingbin 11.

After the mold 24 is disposed on the table 40, the decorative panel 52,which is now in a soft gel or rubberylike state, is separated from themold 24 by flexing the mold 24. The filler mold 34 and the mold member54 are then removed from the decorative panel 52. The carrier board 23is disposed on top of the roller support members 41 and the empty mold24 is then placed on top of the carrier board 23.

The decorative panel 52 is then placed on the carrier board 42, whichrides on the rollers 43, with the decorative panel 52 having its topsurface 56 resting on the carrier board 42 and its bottom surface ontop. In this manner, as previously described for the decorative panel46, the protruding aggregates are removed by the grinding roller 48 asthe decorative panel 52 passes therebeneath due to the constant forceexerted on the carrier board 42 through the flexible member 45.

As shown in H6. 6, the decorative panel 52 has a depending flange 57 inthe same manner as the decorative panel 4650 that there is asubstantially hollow center. The flange 57, which extends around theentire periphery of the body of the decorative panel 52, functions as adrop edge extending downwardly from the body.

As shown in FIG. 6, the drop edge 57 prevents the open mesh members 33from being visible when the decorative panel 52 is installed as akitchen countertop or the like. The top surface of the decorative panel52 is textured or fiat to prevent the resin from becoming opaque due towear.

While the receptacle 26 has been shown and described as having arectangular shape, it should be understood that it could be of any othershape depending on the desired configuration of the decorative panel tobe formed therein. For example, the receptacle 26 could have a circularor oval configuration. Likewise, the opening 53 of the panel 52 could beother than rectangular shaped. The mold member 54 would have the desiredconfiguration of the opening 53.

While the nonrigid member in the decorative panel 46 and in thedecorative panel 52 has been shown and described as the open mesh member33, the nonrigid member could be formed of a mat 58 (see FIGS. 7 and 8)of glass fibers. The mat 58 has the required characteristics orproperties of being nonrigid and capable of permitting the resin to passtherethrough so as not to be a barrier to the flow of the resin.

One suitable example of the mat 58 is a mat of chopped glass strandssold under the trademark UNlFORMAT by Ferro Corporation. This has aweight of 1% ounces per square foot.

All of the steps, which have previously been described for forming thepanel 46 when utilizing the open mesh member 33 as the nonrigid member,would be utilized to form a decorative panel 59, which is the same asthe panel 46 except that the open mesh member 33 is replaced by the mat58. Accordingly, the various steps in forming the decorative panel 59will not be described.

As shown in H6. 8, the panel 59 has its top surface flat or textured dueto the receding of the resin around some of the aggregates in the samemanner as the panels 46 and 52. Likewise, as shown in FIG. 8, the outersurface of flange 60, which forms the drop edge, is flat or textured inthe same manner as the outer surfaces of the flanges 47 and 57 of thepanels 46 and 52, respectively.

As shown in FIG. 9, a decorative panel 61 is formed for use as a kitchencountertop, a vanity top, or the like, for example, when an opening 62must be provided within the decorative panel to surround and support akitchen sink, a range top, a washbasin, or other similar structure.Thus, the decorative panel 61 is similar to the decorative panel 52except that the nonrigid member of the panel 61 is the mat 58 of glassfibers rather than the open mesh member 33.

The formation of the decorative panel 61 is exactly the same as utilizedin forming the panel 52 except that the open mesh member 33 is replacedby the mat 58 of glass fibers. Accordingly, the various steps in formingthe panel 61 will not be described. The panel 61 has both its topsurface and the outer surface of its flange 63 textured or flat in thesame manner as shown in FIG. 8 for the panel 59.

An advantage of. this invention is that it reduces the weight of afinished product formed of polyester resin and aggregates. Anotheradvantage of this invention is that it decreases the cost. A furtheradvantage of this invention is that the amount of required grinding toprovide a smooth surface finish is substantially reduced. Still anotheradvantage of this invention is that the panel remains clear ortransparent or substantially clear or transparent irrespective of thewear on the top surface.

For purposes of exemplification, particular embodiments of the inventionhas been shown and described according to the best present understandingthereof. However, it will be apparent that changes and modifications inthe arrangement and construction of the parts thereof may be resorted towithout departing from the spirit and scope of the invention l claim:

1. A method of forming a precast decorative panel including filling areceptacle in a mold with an unset thermosetting resin and aggregates toa selected level, placing a nonrigid porous member within the receptacleon top of the mixture of resin and aggregates, placing a form on top ofthe nonrigid member of smaller size than the nonrigid member and of thesame configuration as the receptacle but smaller size to form asubstantially uniform space therebetween, filling the uniform spacebetween the form and the walls of the receptacle with aggregates and anunset thermosetting resin, curing the unset resin, removing the formafter sufficient curing of the resin has occurred to produce at least asoft gel, and separating the resin including the aggregates and thenonrigid member from the mold after sufficient curing of the resin hasoccurred to produce at least a soft gel.

2. The method according to claim 1 in which the mold is flexible.

3. The method according to claim 1 in which the nonrigid member is anopen mesh member.

4. The method according to claim 1 in which the nonrigid member is a matof glass fibers.

5. The method according to claim 1 in which the unset resin is cured forapproximately 30 minutes at a constant temperature to a soft gel and theform is removed after the resin is cured for approximately 30 minutes toa soft gel.

6. The method according to claim 5 in which the constant temperature isapproximately 72 F.

7. The method according to claim 1 in which the thermosetting resin is apolyester resin.

8. The method according to claim 1 including polish grinding theaggregates extending beyond the resin after the resin is partially curedto a soft gel.

9. The method according to claim 6 including polish grinding theaggregates extending beyond the resin after the resin is cured forapproximately 30 minutes to a soft gel.

10. The method according to claim 1 in which the nonrigid member is of aslightly smaller size than the receptacle.

11. The method according to claim 1 in which the resin is substantiallytransparent.

12. A method of forming a precast decorative panel having an openingtherein including providing a receptacle with sidewalls and end walls,disposing a mold member within the receptacle in a mold with the moldmember being substantially smaller than the receptacle, filling theportion of the receptacle not having the mold member with an unsetthermosetting resin and aggregates to a selected level, placing at leastone nonrigid porous member on top of the mixture of resin and aggregatesexcept for the portion of the mixture between the mold member and theadjacent sidewalls of the. receptacle, placing support bars in theportion of the mixture between the mold member and the adjacentsidewalls of the receptacle, placing a form of the same configuration asthe receptacle but smaller size to form a substantially uniform spacetherebetween on top of the nonrigid porous member and the mold member,filling the uniform space between the form and the walls of thereceptacle with aggregates and an unset thermosetting resin, curing theunset resin, removing the form and the mold member after sufficientcuring of the resin has occurred to produce at least a soft gel, andseparating the resin including the aggregates and the nonrigid memberfrom the mold.

13. The method according to claim 12 in which the mold is flexible.

14. The method according to claim 12 in which the support bars areformed of steel or the like.

15. The method according to claim 12 in which the unset resin is curedfor approximately 30 minutes at a constant tem- 19. The method accordingto claim 16 including polish grinding the aggregates extending beyondthe resin after the resin is cured for approximately 30 minutes to asoft gel.

20. The method according to claim 12 in which the nonrigid member is anopen mesh member.

21. The method according to claim 12 in which the nonrigid member is amat of glass fibers.

22. The method according to claim 12 in which the resin is substantiallytransparent.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent: No.3,608,038 Dated September 21, 1971 Inven Frank R. Smith It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 1, line 12, "countertop" should read counter top line 12,"tabletop should read table top line 19, "tertop" should read ter top"tabletop" should read table top and a comma should be inserted after"tabletop; line 32, "weir" should read Weir line 47, "countertop" shouldread counter top "tabletop" should be table top line 56, "countertop"should read counter top Column 2, line 9, "rubberylike" should readrubbery-like line 14, "countertop" should read counter top line 21,cancel the "hyphen (-l"; line 59, "countertop" should read counter topline 59, "tabletop should read table top line 71, cancel the secondoccurrence of "including". Column 3, line 43, after "view" insert acomma. Column 4, line 17, cancel the hyphen line 19, after "mold" insert24 line 19, "sidewalls" should read side walls line 26, "sidewalls"should read side walls line 55, "value" should read valve Column 5, line17, "then" should read than Column 6, lines42, 54 and 63, "rubberylike"should read rubbery-like each occurrence. Column 7, lines 30 and 39,"countertop" should read counter top each occurrence; line 30,"tabletop" should read table top lines 38, 41, and 43, "'washbas in"should read wash basin line 45, "with" should be within Column 8, lines3, 31, and 37, each occurrence, "sidewalls" should read side walls line68, "rubberylike" should read rubbery-like Column 9, lines 15 and 53,"countertop' each occurrence, should read counter top line 56,"washbasin" should read wash basin Column 10, line 6 after "invention"insert a period; lines50, 57 and 59, "sidewalls" should read side wallseach occurrence.

Signed and sealed this 24th day of October 1972 5M1 Attest:

EDWARD M.FLETCHER,JR. ROBERT COTTSCI- ALK Attesting Officer Commissionerof Patents )RM Po-1050 (10-69) USCOMM-DC scan-Poe fi' LLS. GOVERNMENTPIHNTING OFFICE 1 I955 O3G6-J!l

2. The method according to claim 1 in which the mold is flexible.
 3. Themethod according to claim 1 in which the nonrigid member is an open meshmember.
 4. The method according to claim 1 in which the nonrigid memberis a mat of glass fibers.
 5. The method according to claim 1 in whichthe unset resin is cured for approximately 30 minutes at a constanttemperature to a soft gel and the form is removed after the resin iscured for approximately 30 minutes to a soft gel.
 6. The methodaccording to claim 5 in which the constant temperature is approximately72* F.
 7. The method according to claim 1 in which the thermosettingresin is a polyester resin.
 8. The method according to claim 1 includingpolish grinding the aggregates extending beyond the resin after theresin is partially cured to a soft gel.
 9. The method according to claim6 including polish grinding the aggregates extending beyond the resinafter the resin is cured for approximately 30 minutes to a soft gel. 10.The method according to claim 1 in which the nonrigid member is of aslightly smaller size than the receptacle.
 11. The method according toclaim 1 in which the resin is substantially transparent.
 12. A method offorming a precast decorative panel having an opening therein includingproviding a receptacle with sidewalls and end walls, disposing a moldmember within the receptacle in a mold with the mold member beingsubstantially smaller than the receptacle, filling the portion of thereceptacle not having the mold member with an unset thermosetting resinand aggregates to a selected level, placing at least one nonrigid porousmember on top of the mixture of resin and aggregates except for theportion of the mixture between the mold member and the adjacentsidewalls of the receptacle, placing support bars in the portion of themixture between the mold member and the adjacent sidewalls of thereceptacle, placing a form of the same configuration as the receptaclebut smaller size to form a substantially uniform space therebetween ontop of the nonrigid porous member and the mold member, filling theuniform space between the form and the walls of the receptacle withaggregates and an unset thermosetting resin, curing the unset resin,removing the form and the mold member after sufficient curing of theresin has occurred to produce at least a soft gel, and separating theresin including the aggregates and the nonrigid member from the mold.13. The method according to claim 12 in which the mold is flexible. 14.The method according to claim 12 in which the support bars are formed ofsteel or the like.
 15. The method according to claim 12 in which theunset resin is cured for approximately 30 minutes at a constanttemperature to a soft gel and the form and the mold member are removedafter the resin is cured for approximately 30 minutes to a soft gel. 16.The method according to claim 15 in which the constant temperature isapproximately 72* F.
 17. The method according to claim 12 in which thethermosetting resin is a polyester resin.
 18. The method according toclaim 12 including polish grinding the aggregates extending beyond theresin after the resin is partially cured to a soft gel.
 19. The methodaccording to claim 16 including polish grinding the aggregates extendingbeyond the resin after the resin is cured for approximAtely 30 minutesto a soft gel.
 20. The method according to claim 12 in which thenonrigid member is an open mesh member.
 21. The method according toclaim 12 in which the nonrigid member is a mat of glass fibers.
 22. Themethod according to claim 12 in which the resin is substantiallytransparent.